Runkle joined the company last year and is convinced that in the long run no other energy source can compete with oil, and that the internal combustion engine will be here for a long time, albeit with an entirely new architecture, the OPOC. That’s the word that Runkle kept using regarding the OPOC engine’s design, architecture. That and “disruptive”. The OPOC, according to Runkle, is cheaper, better, simpler, stronger, lighter and cleaner than any other power generating technology now or in the foreseeable future. Cheaper than hybrids and electric vehicles and with a smaller carbon footprint too.

The engine’s width is exaggerated a bit by the other dimensions which are much smaller than a conventional engine of similar power. Runkle showed a slide of a proposed two-module engine, made up of two 75 HP two cylinder modules, that easily fit inside the standard frame rails of a Ford Fusion. The modular design, with an electric coupling clutch between the modules, allows for variable displacement without the frictional loses that current cylinder deactivation systems involve. The second module is simply decoupled and shut off and doesn’t spin when not needed. The modular concept also allows for superior EPA cycle performance since it can do the complete cycle on only one module, and also heats up quicker eliminating a lot of cold start emissions. EcoMotor’s target is to meet emissions standards without specialized catalytic converters that other diesels currently need to comply.

I took a picture of Runkle holding up a mockup of one of the 75 HP modules and it’s remarkably small. Runkle also showed me a suitcase generator, a 10KW emergency generator with a 10-15 HP OPOC, that’s literally the size of a small suitcase. Ten kilowatts is enough power to run most of your home. Because of the low profile, in front engined cars, the OPOC would allow lower hoods and better aerodynamics. In rear and mid engine vehicles, it’s compact size gives more passenger and cargo space. The Fusion concept drawing was with a transverse crankshaft, but Runkle said that with only slight modifications to the frame rails, the 150HP OPOC could fit longitudinally too.

For power generation applications, the modular concept allows scalability that is not possible with current ICEs. If peak demand means you need a 1000HP, that means you run a 1000HP engine all the time. With a modular design, as load increases, more modules can be brought on line and when load decreases, modules can be shut off, saving fuel.

Runkle says they won’t be following Lotus’ model with their Omnivore engine (another two-stroke design which EcoMotors has studied along with 15 other new engines but feels that they all fall short of the OPOC’s potential). Lotus plans to license the technology but not build engines itself. EcoMotors, Runkle says, intends to use Qualcomm’s model. They both sell chip sets they make themselves and they license their technology to others, creating de facto industry standards. EcoMotors will build motors themselves for sale to non-automotive customers. He contends that no matter the application, power generation, marine, pumps, helicopters, diesel-electric locomotives, whatever you need an ICE for, the OPOC is a superior choice. It runs efficiently at both steady speeds, good for power generation and in use in range extended EVs, and under direct load from the driving wheels. OPOC architecture will also be licensed to major automakers and engine manufacturers.

The central location of the electrically operated coupling clutch between the modules seems ideal for integrating an electric motor so I asked about hybrid plans. I was shown a diagram of what they call a “tribrid”, a two module engine with an electric motor integrated into the transaxle. OPOC’s suitability for genset applications and compact size would make it ideal for range extended EVs. While I’m on the subject of hybrids, Runkle and Hurden both said that EcoMotors is not at all involved with the electromagnetic hybrid ICE engine that Bill Gates and his associates have patented through Intellectual Ventures, his IP enterprise.

Though they’ll gladly sell motors and technology that would be used in hybrid vehicles, Runkle is convinced that the OPOC is by itself superior to hybrid and EV technologies in terms of overall cost and environmental impact.

In comparison to conventional ICEs, not only does the simpler design mean lower production costs, Runkle anticipates that the cost of building the production line itself will be 30% lower than with a conventional engine, and converting an existing plant to OPOC production would yield even greater savings. The lower cost of entry is a selling point to developing countries like China and India.

With Runkle’s background running Buick’s racing program, and Colleti’s background building SVT products at Ford, I asked about motorsports and performance cars. At first Runkle, who headed development of some fairly high performance production, concept and racing cars, said that he’d already done that and was interested in an efficient, cost effective powerplant. Then he smiled and said, that the OPOC would make a “phenomenal racing engine” and proceeded to tick off what made it an ideal racing powerplant: high specific output, low weight, low aero, and low cg. He then said that it would “probably be outlawed” and that in any case racing was “not in the budget”.

When I asked for a time frame to production, Runkle said that he hoped there’d be OPOCs in production in some form within 3 years. When I asked him where he saw the company in 10 years, he said that it’d be a billion dollar company, selling millions of engines, that famous car companies and well known engine suppliers would be producing OPOCs of their own designs, making their own improvements, paying royalties.ed.

“We feel that we have the engine and technology for all reciprocating ICE’s.”

When I alluded to Zhongding’s “investment”, Runkle took pains to say that they “are not an investor, they are a customer”. EcoMotors is developing a variant of their engines for Zhongding and that the letter of intent is being formalized into a contract.

In terms of deals with other companies, the OEM automakers have shown “a lot of interest” even though EcoMotors has not made a lot of presentations, pitches and road shows. During our interview, Runkle was running through an abbreviated PowerPoint presentation they use for investors and potential customers, but so far the haven’t really marketed the concept. They have no communications staff and what marketing they are doing is being handled by an outside firm, PCGCampbell.

Runkle said that nobody’s thrown them out of an office yet, but that they want to be sure that their game is good before they start marketing the idea seriously. A $350 market is the big leagues.

In the second chapter of Pirke Avot, The Ethics of the Fathers, the concept of wisdom is discussed. Rabbi Shimon says, ” Who is wise: One who sees something from its birth”. The ability to see the end from the beginning, the possible consequences or opportunities from a situation, both the good and the bad, is indeed one of those things that separates the wise from the foolish. I’m sure that from their excitement, EcoMotors thinks that they are midwifing the birth of a great new thing. Time will tell how wise they are.

Peter Hofbauer mentions the Junkers engine in one of the videos on the EcoMotors site and though I didn’t take a photo of it, there was a cylinder for a Junkers engine in their offices at Roush.

There aren’t any exotic materials involved,normal engine stuff. The only thing cutting edge is the combustion chamber. What they do have are modern engine controls which they’ve expanded to include the electrically controlled turbo, and what Runkle said was some very expensive computer modeling of gas flow.

To clarify, that’s a plastic mockup, so don’t get the wrong idea. It’s lightweight yes, but I’m not sure that he’d be able to heft a real 75 HP OPOC that easily. The 300HP version is 300lbs. So assuming that the power/weight ratio stays pretty even that means the a 150HP two module engine would weigh about 150 lbs. A Honda Civic B20B engine is about 320 lbs.

So that would put it more or less about as heavy as, or a little more than, Mazda’s contemporary rotaries, but with a torque advantage and a packaging disadvantage. This is the early stages for them, though.

I don’t think I see this as mutually exclusive with hybrid powertrains, though. There’s a lot of mileage in managing the engine’s output such that a) it’s running at peak efficiency when you need it and b) it’s not running at all when it’s not required.

Other than the opposed piston, opposed cylinder layout and modular “architecture”, you barely mentioned one, and possibly two, other features. It’s a two stroke, and it might run on diesel. That brings up three concerns, noise, vibration and durability. Were those covered in any depth?

Read the preceding post for comments on durability. I’d imagine that noise and vibration are quite good as it’s a balanced design, but this is of course something that needs to be tuned in-application.

In terms of noise, I don’t believe that the test cell had any mufflers so it’s hard to say how noisy the engine is other than a Harley with open pipes is louder. It was loud enough to need earplugs for protection but we could hear each other talk.

As for vibration, as I wrote in the previous article about the OPOC, the engine is remarkable for its smoothness.

You can watch for yourself in the video how smooth it runs, and hear how loud. I got a shot of the crank pulley and belt drive just to show that it really was running, since there was no vibrations that I could see that the engine was making.

It was really uncanny. I’ve been around motors for along time and you’re always used to a little shake, rattle and roll, but the OPOC was rock steady.

The modularity is certainly interesting. I’ve always wondered why Subaru, BMW or Porsche has never developed a modular engine from their boxer engines (since flat engines are an ideal config for 2-cylinder engines). Flat twins arranged in 2,4,6,8 cylinder configurations separated by an electronic clutch able to provide modular power.

It would be perfect for hybrid and HCCI application. Each module can run in ideal load, one can charge the battery while the other drives power to the wheels. In addition, each module can run under ideal load suitable for HCCI.

However, I’m trying to understand the benefit of the OPEC design. Having a clean and efficient two-stoke engine has always been the holy grail. But this engine still has side-valves which have been notorious hurdle for inefficiency and reliability. I also have to wonder about the complexity of maintenance and upkeep of that engine given its seeming complexity.

Either way, very interesting stuff, would love to see an adventurous major automotive maker take this concept to the next step to production reality.

This one will be interesting to watch. I’ve seen many engine concepts come and go over the years, though, so I think its sales success is not assured.

The earliest opposed-piston car that I’ve heard of is the 1909 Gobron-Brille Tourer, a running example of which is at the Nethercutt Museum in Sylmar, CA:
http://nethercuttcollection.org/Cars.aspx?era=antique

I am a big fan of Fairbanks Morse opposed piston marine diesel engines, and know them well. they would run forever with very few problems. Can you provide any more details of how this thing works,as I don’t understand it. A picture of the insides would be helpful.
We did have a few stack fires.

I don’t have a picture handy but where the FM motors would have two crankshafts (and compare that to a Napier Deltic with three!) this has the opposing piston on a looooong opposing rod that connects to the crank.

FM’s motor was just a bit too early for the conversion from steam to electric energy for passenger rail service or else the lower output crank would have been perfect for generating head end power.

Racing: yes. They need somebody with sports car racing experience. Roush and somebody with a Buick background may think in terms of what will “probably be outlawed” but the road racing world is proving to be very open to non-boring concepts… Audi’s diesels, Mazda’s hybrids…

I’m thinking this size and shape might make the most sense in mid or rear-engine configurations…. so put a big trunk in front under the regulation mandated hood. That would make a lot of sense anyway…..

Thanks Ronnie, this is one of my big questions – how well would it work as a gas engine, particularly with respect to NOx?

For diesel applications, do they have any doubts about being able to make Tier II Bin 5 passenger car standards with a relatively decent-sized engine (say 150-200hp) without the lean-cycle / urea injection trickery?

They hope to be able to meet the ’10 standards with no add-ons. What they’re doing now is tuning the combustion process. The piston design, intake and exhaust port design, and electrically controlled turbo all have to work together to get maximum fuel burn and gas exchange.

This isn’t magic and these people aren’t cranks. The engineering is solid and what they’ve described isn’t the technobabble you get from the “100mpg carburetor” nutters. The engine design is unorthodox and there are still a million reasons why it might never show up in a production car, but it clearly exists and works. They also have a solid, well proven business plan c.f. the Qualcomm model used as inspiration.

Not at all. The OPOC runs, and has dyno generated data to prove it. Hofbauer designed the first high speed diesel passenger engine for VW, and the rest of the team there are also respected engineers and automotive people. None of their claims are outlandish:

For a given power level, the opoc™ engine is 30-percent lighter, one-quarter the size, and achieves 50-percent better fuel economy compared with a state-of-the-art, conventional turbo-diesel engine.

It’s a very low friction engine. For the same displacement, pistons in an OPOC travel half the distance they do in a standard reciprocating ICE. The primary sources of engine friction are the piston rings against the cylinder wall and the main crankshaft bearings. By reducing piston travel they reduce the friction there and because of balanced forces on the crankshaft they only need two main bearings.

If you check the wikipedia link I gave above, you will see that OPPOC is an extension of existing technology, that has been used in, among other things, Navy ships, for a long time. The problems lie in getting it to comply with EPA regulations, and mass producing it for the automobile market, at a reasonable cost, and with sufficient reliability. Navy ships carry engineers whose job it is to keep the engines going. Cars are expected to run for years with minimal maintenance.

Many engine technologies have come an gone over the past century. Only a few have lasted. The Wankel is just the latest example of one that fell short.

I don’t think they could fit this in the RX-8. I remember the first time I saw how the rotary is placed in the RX-8 and it really drove home that it’s real advantage isn’t power or smoothness but packaging. It’s a trim engine; the OPOC is more awkwardly shaped.

I think the rotary would do well paired to something like Honda’s IMA. It’s so short and thin that you could sandwich a sizable electric motor very near it and the crank without disrupting it’s balance.

I am truly jazzed.
The joking comment about the engine possibly being outlawed in racing gave me chills!

This shows that cars are becoming as quickly outdated as computers.
Well, sort of.
But really, it is hard putting down money for a car today when you more than likely will suffer buyer’s remorse the next year.

I was looking forward to the 2011/12 Focus with EcoBoost…now not so sure.
I think this could be a really fun, fast and affordable engine.

One BIG issue: 4cyl engines inherently do not allow intake to get out the exhaust. In all 2 stroke designs the exhaust is “pushed” out by the intake charge which is pressurized by either a super- or turbo-charger (as in old detroit diesel engines), or crank case (like dirt bikes). I am suspicious of the emissions claims. This is essentially one of the reasons that the Mazda rotary took a break; Emissions restrictions.

Call me a skeptic but I’ll believe it when I see it… PASS EPA RESTRICTIONS.

I’m apalled at the way Runkle uses the word “disruptive”. It’s understandable that Ronnie didn’t catch him, perhaps he’s never read the Christiansen’s book. In actual term of art use, a disruptive technology is a technology that is in every way WORSE than the one generally available across a market. If OPOC were disruptive, it would’ve been the opposite of the Runkle claims: heavier, dirtier, less efficient than conventional engines. It might have costed $20 for a 100 bhp engine, but it would not be able to take on market leaders on the basis of performance. An innovation with the claimed parameters of OPOC is called “sustaining”, not “disruptive”. It’s elementary!

I do not think Runkle is that ignorant. That leaves deceptive. He tries to ride the coat-tails of disruptive technologies of the past in the mind of people who heard about them but do not know what they were.

The term has become genericized and now basically means anything that poses a substantial threat to the incumbent technology. VCs use it in this way all the time now. I don’t think he’s being willfully deceptive in that regard.

Since I have nothing intelligent to add, I’ll say that picture reminds me of the Bob Ryan episode of Entourage. “Hey Eric, see this engine model? Elizabeth Taylor gave it to me as a gift after she and Sinatra left one of my parties together. Boy, those were the days. Hey, how about a movie with an engine, does that sound like something you might be interested in?”

I suppose that computer-controlled intake pressure (either super or turbocharged) made this “rebirth” possible. But, as mentioned by Dr. Strangelove, 2-Stroke technology has its limits, and this engine has (in a few iterations) hit those limits. It has no where to go, with the exception of a range-extender operating in a narrow RPM band, where the charge scavenging can be precisely predicted and controlled.

As compared to the scavenging of the OPOC engine,
the pattakon OPRE engine has built-in, piston-type (with almost zero dead volume), “volumetric” scavenging pump.

The built-in “volumetric” scavenging pump combined with the extended dwell of the pistons at the Combustion Dead Center (CDC) allows the direct injection Diesel OPRE engine to keep its torque in a wide rev range, from below 1000 rpm to above 6000 rpm.

more compact,
lighter,
simpler,
cheaper,
is based on “built-in” scavenging pump of the piston type,
has a wider rev range,
is more vibration-free,
provides additional time to the fuel to get prepared and burned more efficiently (and in-time),
has better lubrication, etc,

For more details (videos of the OPRE prototypes running on Diesel fuel, dimesnions, weight etc): http://www.pattakon.com/pattakonOPRE.htm

My congratulations sir, this is the best stuff on engines, variable valve lift, variable compression ratios, etc. etc, that I’ve ever seen. Amazing. It does expose the OPOC engine for the mechanical nightmare I believe it to be, ever since I went to their website following an article in Car and Driver magazine several months ago. I’m afraid those long spindly connecting rods and wrist pin holes through the cylinder walls on the OPOC just don’t do it for me.

Your solution is far more elegant, although I do not see why it would be more vibration free than the OPOC, which is completely symmetrical, unlike yours (the gears are on one side only). Nor is yours so easy to package into modules, and it does require two crankshafts. The Junkers engine as realized by Fairbanks Morse had one crank about 10 degrees ahead of the other for TDC considerations, I believe. That destroys absolute symmetry, but may offer other benefits.

I don’t see why you couldn’t use forced air scavenging by utilizing a turbo run by the exhaust gases, because just using the upper piston to pump air seems to me to give only a 1:1 ratio for scavenging. Am I missing something?

In any case, your variable valve timing and lift, and tweaks to allow 330 rpm idle speeds are superb realizations, in my opinion. They make everything else I’ve seen look crude. As you say, BMW and Nissan’s solutions look awful compared to yours.

I hope Loughborough University is helping you, and wish you the very best of luck. Your only problem is that your designs are so elegant, you may suffer from the Not Invented Here Syndrome typical of manufacturers.

The unconventional geometry of OPRE (its crankshaft is disposed between the wrist pin and the combustion chamber while the wrist pin of conventional, and of the Fairbanks Morse opposed Diesel, is disposed between the crankshaft and the combustion chamber) shifts the combustion to the slow dead center.
The high pressure gas into the combustion chamber loads the connecting rods of the OPRE only in tension.

Compared to the conventional (and to the Fairbanks Morse opposed diesels), the OPRE engine provides some 30 to 40% longer piston dwell at the Combustion Dead Center (CDC), compared to the OPOC the OPRE provides some 20% longer piston dwell at the Combustion Dead Center, i.e. additional time for the preparation of the mixture and the combustion of the fuel at better thermodynamic conditions.
The efficiency of an engine depends heavily on the amount of the fuel that is burned with the piston still near the Combustion Dead Center.

After 4500 rpm the power output of all direct injection Diesels ((and the Fairbanks Morse and the Junkers) drops steeply because a good part of the fuel is burned late (when the piston is away from the CDC) and inefficiently. OPRE’s geometry shifts this limit above 6000 rpm and proportionally the peak power; it also improves the medium revs thermal efficiency of the direct injection Diesel.

With one more crown at the wrist pin side of each piston, a pair of reciprocating volumetric scavenging pumps is created at the two ends of the cylinder. The ratio squared of the bore at the pump region to the bore at the combustion region of the cylinder defines the scavenging ratio. Besides their simplicity, efficiency, lightweight and low cost, OPRE’s integrated scavenging pumps offer a flat torque curve along a wide rev range, from very low revs to high revs now inaccessible for Diesel engines.

The transfer of the wrist pin – i.e. of the thrust loads – away from the hot combustion chamber and away from the ports, solves another problem of the opposed piston engines: it allows “four stroke” like lubrication and oil consumption.
OPRE’s piston skirt can avoid the touch with the hot cylinder wall because the thrust loads are taken at the other side of the piston, onto the cool, rid of slots and well lubricated cylinder wall of the scavenging pump.
In comparison, the piston skirt of the conventional opposed piston engine thrusts heavily onto the hot, especially at exhaust side, cylinder wall, around the port area where the openings restrict the contact surface, requiring plenty of lubricant and inevitably resulting in lubricant consumption.

The short distance of the two crankshafts of the OPRE – for a given piston stroke – makes robust, efficient and light the coupling of the two crankshafts.

The animations and plots at http://www.pattakon.com/pattakonOPRE.htm and at http://www.pattakon.com/pattakonOPRE2.htm may help.

These are a few of the differences between the OPRE and the Fairbanks Morse opposed diesels.

I’d be interested to know if they’ve actually tried the modular decoupling side of things. Crankshaft torsional vibrations can take months or even years to solve,even with only a one piece crank. M guess is they’ll need a TV damper for each stage.

Vibrations:
The arrangement of the basic module of the OPOC engine generates 2nd order inertia moments by the offset between the two cylinders (at TDC the 2nd order forces generated by the two pistons of the one cylinder are maximum and at the same direction; with the opposite direction 2nd order inertia force generated by the pistons of the other cylinder, it results the 2nd order unbalanced inertia moment).
Besides, the mounts of the OPOC engine take a strong 2nd order inertia torque (look it from the energy viewpoint: the total kinetic energy of the four pistons of the OPOC is zero at TDC and strong at the middle stroke, which means as heavy inertia torque as the conventional four in-line with similar pistons and stroke).
But even if you accept the 2nd order unbalanced inertia moment and torque of the OPOC, there are other issues too: in order to balance the 1st order inertia forces of the OPOC it is necessary to use piston assemblies of similar reciprocating mass (which is the mass of the piston, the mass of the piston pin and the mass of the upper side of the connecting rod). That is, you have to increase the mass of the internal pistons a lot, in order to keep the OPOC enegine balanced.

Assymetry:
The fact that the one cylinder of the OPOC operates with the internal (or quick) piston controlling the exhaust ports while the other cylinder operates with the external (or slow) piston controlling the exhaust ports is anything but symmetrical: the one cylinder operates with different “timing” than the other one. You may compensate the difference at some revs, yet you cannot at a wide rev range.
The OPOC engine is not “completely symmetrical”.

Now take a look at the OPRE: in case of symmetric timing (the prototypes work with symmetric and asymmetric timing in the videos), i.e. with the two pistons at the TDC the same moment, the engine is perfectly balanced as regards its inertia forces and moment. See the video with the cigarette standing on the OPRE engine while two electrical drills drive the two cranks.
With some 7 degrees offset between the two crankshafts (in order to have similar asymmetry of intake to exhaust timing to the 10 degrees used in the old Junkers engines) the balancing of the OPRE remains excellent. 7 instead of 10 degrees? Note that the slow combustion dead center is where the combustion takes place in OPRE, while the fast dead center is the dead center where the combustion takes place in the old Junkers.

Yet there is a 2nd order inertia torque (similar to the 2nd order inertia torque of the typical four in-line engine).

2nd order inertia torque in OPRE:
Yet, in case of symmetrical load (for instance in case an electric generator is driven by the one crankshaft while a similar electric generator is driven by the other crankshaft at the opposite direction) the 2nd order inertia torque is cancelled inside the cylinder. I.e. the mounts of the OPRE engine are rid of inertia forces (of any order), of inertia moments (of any order) and of inertia torques (of any order too).

Furthermore: in case of symmetrical load the power pulses (the useful torque) on the engine casing (i,e. on the cylinder of the OPRE) from the two crankshafts cancel each other, leaving the mounts of the engine rid not only from inertia vibrations but also from power pulses vibrations. Some companies present their Wankel-range-extenders as having the best NVH properties, yet their range extenders suffer from power pulses vibrations. The OPRE with the symmetrical load is better in NVH properties because it solves internally the power pulses issue.
In case of symmetrical load, the synchronizing gear wheels between the two crankshafts of the OPRE remain actually unloaded (small friction etc)

The OPRE can operate either with asymmetrical or with symmetrical timing between the intake and exhaust ports. This is because OPRE is based on volumetric scavenging pumps.
The OPRE can also use forced induction, but this solution makes narrow the efficient rev range.
Even without forced induction, the OPRE is not restricted to 1.0 scavenging ratio. The OPRE III prototype, for instance, has 80mm bore in the “combustion side” of the piston and 90 mm bore in the “cool” side of the same piston. This means a 1.26 scavenging ratio.

Think of the OPRE driving two counter-rotating propellers, like in the Portable Flyer at http://www.pattakon.com/pattakonFly.htm
The pilot carries the OPRE engine with the propellers. The pilot is perfectly rid of any kind of vibrations (inertia vibrations and power pulses vibrations). The twin crankshaft is a solution, not a problem.
The OPRE fits better to such application (portable flyer, electric generation set, range extender etc).
For car engines (wide rev range with loads varying from very light to heavy) the VVA systems, the VCR systems etc presented in pattakon web site fit better.

The Loughborough University is not helping us. They just presented, at Engine Expo 2009, at the Open Technology Forum, in front of the pattakon stand, their theoretical approach and calculations regarding the benefits of extending the piston dwell at the combustion dead center, while we had there the prototype engines ready to run on Diesel fuel. It was like a joke.

The packaging of the OPOC vs OPRE: just think of the additional equipment the OPOC needs, like the turbo, the electric motor etc, while the OPRE is self-sufficient: the prototypes operate without electrical system and without an exhaust system.
For the same stroke the OPRE module is way shorter (more than 30%) than the module of the OPOC.

To Ronnie Schreiber:
Thank you.

We have no data for the emissions of the OPRE.
The OPRE prototypes were made by simple means, as a “proof of project”. To take an idea: the injection system (i.e. the high pressure pump and the fuel injector) costs some US20$.
On the other hand, theory says that if the OPOC can pass the 2010 emissions standards, the OPRE using the same injection system will pass easier, because the extended dwell of the OPRE pistons at the combustion dead center provides additional parameters to further optimize the combustion.

We think the OPRE portable flyer can change the world. Yet we have to fly first, to prove it.

The OPRE is based on an unconventional geometry: its crankshaft is disposed between the wrist pin and the combustion chamber to shift the combustion to the slow dead center.
The wrist pin of the conventional – the Fairbanks Morse opposed diesels included – is disposed between the crankshaft and the combustion chamber and the combustion takes place at the quick dead center.

The plots and the animations at http://www.pattakon.com/pattakonOPRE.htm and at http://www.pattakon.com/pattakonOPRE2.htm may help (start with the gif animation ar http://www.pattakon.com/pre/PRE6b.gif ).

With its unconventional geometry, the high pressure gas into the combustion chamber loads the connecting rods of the OPRE only in tension.

The extended piston dwell at the Combustion Dead Center or CDC (some 30 to 40% longer than the piston dwell of the comventional, and some 20% longer than the “piston dwell” of the OPOC) provides additional time to the fuel to get prepared and burned more efficiently (the efficiency of an engine depends heavily on the percentage of the fuel that is burned with the piston still near the Combustion Dead Center).

After 4500 rpm the power output of all direct injection Diesels drops steeply because a good part of the fuel is burned late (when the piston is away from the CDC) and inefficiently. OPRE’s geometry shifts this limit above 6000 rpm and proportionally the peak power, it also improves the medium revs thermal efficiency of the direct injection Diesel.

With one more crown at the wrist pin side of each piston, a pair of reciprocating volumetric scavenging pumps is created at the two ends of the cylinder. The ratio squared of the bore at the pump region to the bore at the combustion region of the cylinder defines the scavenging ratio. Besides their simplicity, efficiency, lightweight and low cost, OPRE’s integrated scavenging pumps offer a flat torque curve along a wide rev range, from very low revs to high revs now inaccessible for Diesel engines.
If disarable, the OPRE can use the scavenging/supercharging system of OPOC.

The transfer of the wrist pin – i.e. of the thrust loads – away from the hot combustion chamber and away from the ports, solves another problem of the opposed piston engines: it allows “four stroke” like lubrication and oil consumption.
OPRE’s piston skirt can avoid the touch with the hot cylinder wall because the thrust loads are taken at the other side of the piston, onto the cool, rid of slots and well lubricated cylinder wall of the scavenging pump.
In comparison, the piston skirt of the conventional opposed piston engine (as well as the piston skirt of the internal piston of the OPOC) thrusts heavily onto the hot, especially at exhaust side, cylinder wall, around the port area where the openings restrict the contact surface, requiring plenty of lubricant and inevitably resulting in lubricant consumption.

It is also the short distance of the two crankshafts of the OPRE – for a given piston stroke – that makes robust, efficient and light the coupling of the two crankshafts.

These are a few differences between the OPRE and the old Junkers and Fairbanks-Morse opposed piston engines.

I prefer the way Honda does it using the flywheel as the gen/braking/motor on small engines.
It does it so seamlessly with massive torque, that this attempt is a bit off the dusty industrial supply shelfs of left over will-call orders.
Simply study closely the early Insight 10 years ago.

After the comparative tests versus the Toyota Prius, the typical comment for the Honda Insight is: “too little, too late”.

EcoMotors / OPOC risk their time and money to make something new.

And if “this attempt is a bit off the dusty industrial supply shelfs of left over will-call orders”, then, what about the Wankel Rotary?
Mazda can keep on with the Wankel, making all these bold claims about its “next” generations.

Why not to prefer the OPOC engine with all the advantages of the Wankel and none of its numerous drawbacks?

Isn’t it as balanced as the Wankel?
Makes the OPOC basic unit as many combustions as the Wankel two-rotor of Mazda?
Has the OPOC low friction because of the small total force on the crankshaft main bearings?
Isn’t the OPOC lightweight enough?
Has the OPOC combustion chamber several times more compact in order to:
-Complete the injection and finish the combustion timely;
-Avoid the heat loss through the two-to-three times more wall area of Wankel;
-Avoid the loss of the gases through the problematic seals of the Wankel;
-Be used as a gasoline or as a Diesel, tiny or large.

I’ve driven the the Insight as a owner over ten years ago. The ride will never be envied. Higher air pressure to reduce tire rolling resistance, stiffly sprung for battery weight, it’s a city commuter at best.
Designed 5 years prior. With fuel price not really an issue till now.
It did do 110 mph, and get 60mpg + in normal cruise.
Same with Mazda’s twin turbo Wankle the size of bowling bag, can
make a grown man cry with fear going full out through the gears.
These two examples are probably before most were old enough to
operate a two stroke scooter.
Major outboard companies know better to continue with two stroke, as have snowmobiles with 4 stroke as the the first gen Rx1 I use from 2003.
The weight is no longer the issue when it was only 50 lbs difference. The life span equals automotive durability with 4 stroke.
To pursue 2 stroke, diesel wise, go for it, at least GM has cleaned up it’s output, but comes at a high maintenance step with it’s exhaust filter systems.
The OPOC does have unique crank, I’ll give it that. Now go for 4 stroke to cover that design at the same time. Plus the fact it’s much easier to control emissions and fuel rate. To me, the piston length is longer than need be by 2 inches if examples are one to one in drawing.
Make them power light aircraft to make a stunning impact besides just generator power packs.
I witnessed 2 stroke generators in Germany, and it’s not a pleasant sound experience.
Simply modifying simple reed valve compressors which these basics are, need to have a cool dense positive charge waiting to get in vs a negative internal pressure to open a reed valves.
A turbo will not see enough flow at exhaust until the rpms are almost 60 percent of max rpm.
I’ve built drag racing engines to 80lbs of boost, and it doesn’t get there easy w/o a lot of destruction along the way.
REgardless, engine development is never boring.
Cheers

Being in the dragsters business, is being at the front of the science/tech. 80 lbs of boost is hard to deal with in a 4-cycle where cylinder-head and studs and exhaust valves etc are ready to fall apart.

The PatOP engine (an explanatory video-animation is at http://www.pattakon.com/patop/PatOP.wmv ) has only the crankshaft undergoing the boost; the connecting rods are loaded in tension only, the crankcase and the liners are under no loads (neither combustion nor inertia).
Only the crankshaft, the con-rods and the crankpin bearings can break; there is nothing else under the boost.

Besides, the piston-type pump inside the PatOP can provide what the turbo cannot at low-medium revs, as you say.
80 lbs boost flowing from the turbo into the volumetric pump of the PatOP and then into the cylinder, where only the crankshaft and the con-rods need to be replaced by stronger to make a Dragster.
Your experience can see what are the disadvantages of a PatOP dragster versus the current ones.

In a two-stroke engine, the intake port and exhaust port air flows and exhaust gases. In Polish, these ports are called: a window intake and exhaust window.
Going forward as a Polish name, the engine new4stroke, these ports can be called windows.
A computer program to calculate all the values of geometric newly proposed four stroke engine with piston valves, can be called ” Windows of 4 stroke engine” .It is such visualization and geometric sizes are most needed for the proper design of engine .I should give the possibility of calculating the correct dimensions for the engine rc aiplane modeller and the engine to the ship.
I do not know how much would cost such a software , “Windows 4 stroke engine “, but it should be good to allow for proper design of this engine.
Doing so designed engine is then very simple.
I present my software but incorporating only some of the main parameters of the engine. Here you can change the input data, but the results we are only a little transparent table in EXCEL.
http://www.new4stroke.com/volume.zip
Useful to the version of Windows ..